Automobile Engineering in ME
The rigid suspension is beneficial when

It is desired to improve tyre to ground contact characteristics
It is desired to have more flexibility in design
Large changes in load make it necessary to have a large suspension stroke
It is desired to reduce the unsprung mass

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Automobile Engineering in ME
The main function of the tread pattern on tyre is that

The crests between the tread grooves absorb road noise
The tread grooves pass air between the tyre and road surface, thereby preventing tyre from overheating
In wet conditions, the tread grooves expel water that is drawn between the tyre and road surface
The tread pattern protects the tyre's inner carcass from small stones and pieces of glass

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